Be sure to follow these preliminary steps, these are very important for Cupido to work flowlessy!
In config.yml of TAB be sure to enable unlimited nametag mode by setting it to true.
Always in config.yml of TAB under "player" in "placeholderapi-refresh-intervals:" set the placeholder request of %cupido_health% to 50.
In groups.yml of TAB head over to your desired group and add the placeholder.
(the unicodes will remove the black background for the hologram)